Template follower mechanism

ABSTRACT

A mechanism for use in automatic and template-controlled machines tools and especially in automatic sewing machines, in which a driven magnetic roller rollalong the peripheral edge of the template, to provide an automatic and safe driving of the roller out of the internal corner. This mechanism includes a gear pinion coaxial with the magnetic roller and either one toothed segment pivoted eccentrically on the template, or two toothed segements, if the magnetic roller must roll alternately in two directions along the template. These two toothed segments pivoted adjacent the internal corner of the template, act like a lever when the gear pinion meshes with one of the toothed segments after entering the internal corner, in order to push the magnetic roller out of the corner into a direction of a course determined by the curve of the template and the magnetic roller.

Jiinemann [45] Sept. '11, 1973 TEMPLATE FOLLOWER MECHANISM [75] Inventor: Hubert Jiinemann, Bielefeld,

[30] Foreign Application Priority Data Sept. 26, 1970 Germany P 20 47 438.8

[52 US. Cl. l12/l2l.l2, 74/569 [51] Int. Cl. D05b 21/00 [58] Field of Search ll2/12l.l2, 121.15, l12/102',74/569; 266/23 E, 23 B; 33/23 H, 23

[56] g References Cited UNITED STATES PATENTS 9/ 1968 3/1969 Scholl et al.- 74/569 Laws ..1l2/l2l.l2X

Primary Examiner-James R. Boler AttorneyJacob L. Kollin [57] ABSTRACT A mechanism for use in automatic and templatecontrolled machines tools and especially in automatic sewing machines, in which a driven magnetic roller rollalong the peripheral edge of the template, to provide an automatic and safe driving of the roller out of the internal corner. This mechanism includes a gear pinion coaxial with the magnetic roller and either one toothed segment pivoted eccentrically on the template, or two toothed segements, if the magnetic: roller must roll alternately in two directions along the template. These two toothed segments pivoted adjacent the internal corner of the template, act like a lever when the gear pinion meshes with one of the toothed segments after entering the internal corner, in order to push the magnetic roller out of the comer into a direction of a course determined by the curve of the template and the magnetic roller.

' 4 Claims, 6 Drawing Figures PATENTED SEPI H873 SHEET 3 BF 3 TEMPLATEFOLLOWER MECHANISM BACKGROUND OF THE INVENTION This invention relates to a mechanism in templatecontrolled machine tools and particularly in automatic sewing machines, in which a magnetic roller rolls along the peripheral edge of the template, to provide an automatic and safe driving of the roller out of the internal corner of the template.

Auxiliary devices are necessary in templatecontrolled machines of the above mentioned type to prevent the idling of the magnetic roller in the internal corner after the arrival. This idling of the magnetic roller occurs in an extremely high extent if the radii of the roller and the rounding of the internal corner of the template are equal and the peripheral edges forming the internal corner have a course angle of less than 90. Thus, the magnetic roller rests with a great part of its circumference against the edge of the template.

When the roller approaches an internal corner, the uniform speed of the roller along the template is called in question. As a result of the increased magnetic attraction occuring when the roller approaches the corner, the' roller can perform a sudden jump forward and thus it can abut permaturely against the diverging part of the template. In thise case, for example, in automatic sewing machines, the stitches to be sewn in the corners of the workpiece would be longer than normal.

Proposals have already been made to prevent this shortcoming. Following a suggestion, the sudden jumpingof the magnetic roller can be prevented by means of a flat spring, which is secured to the template diagonally to the corner and which is tensioned when entering the internal corner. Furthermore, this flat spring serves for the reduction of the increased adhesion occuring in the internal corner, in order for the roller to continue its travel in the new direction of a course without stopping.

Should the roller be stopped in the corner of a tem plate by magnetic intensity, and urged out of the corner by external influence, the roller suddenly detaches from the rolling surface of the template as a result of the abrupt reduction of the magnetic intensity, whereby the desired uniform speed of feeding of the roller will not be maintained. This caused by using an electromagnet which temporarily acts upon the roller in order to cause it to be forcibly driven out.

These proposals are made in the British Pat. No. 1,108,141.

It is a primary object of this invention to provide a mechanism which will prevent the magnetic roller from idling in the internal corner of a template and which will cause a shockless forcing out of the roller from the internal comer, in order to avoid an additional acceleration of the magnetic roller.

It is a further object of the invention to provide a mechanism which is suitable for use in template controlled machine tools or automatic sewing machines in which the magnetic roller can rotate in two directions in orderito roll it along the template in two directions.

Itis further object of the invention to provide mechanisms of the above mentioned kind, which are simple in construction and reliable in operations.

SUMMARY OF THE INVENTION The objects mentioned above are substantially attained by means of a mechanism having a rotatably driven gear pinion, which is coaxially se ured to a magnetic roller abutting against the template, and, a toothed segment eccectrically pivoted on the template for acting like a lever when the gear pinion meshes with the toothed segment after entering the internal corner in order to push the magnetic roller and the gear pinion out of the comer into a direction of the course determined by the curve of the template. The toothed seg-' ment is received by an adjustable eccentric bolt in order to eliminate and adjust the clearance between the toothed segment and the gear pinion. A stop means cooperates with the toothed segment. A tension spring is provided for moving the toothed segment into the normal position after demeshing of the gear pinion from the toothed segment.

A second toothed segment is necessary if the gear pinion and the magnetic roller are driven in a clockwise direction.

Other objects and advantages of the invention will be apparent from the following description and from the accompanying drawing.

BRIEFDESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational viewpartly in section of a template-controlled automatic sewing device for continuously sewing cuffs or the like workpieces.

FIG. 2 is a perspective top plan view of one embodiment of the mechanism placed on the template and close to the internal corner of the template;

FIG. 3 is a top plan view of the embodiment shown in FIG. 2;

FIG. 4 is a section taken along line IV IV of FIG.

FIG. 5 is a top plan view of a modified embodiment of the mechanism according to the invention, and

FIG. 6 is a section taken along line VI VI of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. I, the device there shown, includes a turntable l, which is driven by a motor 2, and interchangeable workpiece clamping means 3 clamped to the turntable l, for holding the workpieces 4 by means of clamps 5, and templates 6 secured to the bottom surface of the clamping means 3.

A magnetic roller 8 (FIG. 2) secured to a driven shaft 9 abuts against a peripheral edge 7 of the template 6. The shaft 9 is surrounded by a field coil 10 which is received in a supporting arm 12 carrying a sewing machine 11. The shaft 9 is driven by a motor 15 via bevel wheels 13, 14. The turntable l is carried by a shaft 16, which is pivoted in .a frame 17 provided with a jib l8. Pivoted to the jib 18 is a horizontal link arm 19, the free end of which is linked to the supporting arm 12. A motor 22 drives the needle bar 211 of the sewing machine 11. The needle bar 21 carries a needle 20 and is disposed coyxially with the shaft9. Secured to the shaft vided for holding the toothed segments 28, 29 in a normal position. The ends of the coil springs 21 are slipped over angled spring supports 32, 33. The spring support 32 is screwed to the toothed segment 28 and secured against rotation by means of a nut 34, and the spring support 33 is screwed to the template 6.

The operation of the mechanism is as follows:

When the magnetic roller 8 enters an internal corner of the template 6 (FIG. 3), the gear pinion 23 meshes with the toothed segment 25, which hereby rotates about the bolt 24. As a result of the lever action occuring thereby, the magnetic roller 8 is urged out of the internal corner into the direction of the course indicated by an arrow. After disengagement of the teeth, the eccentric toothed segment 25 is drawn into the normal position and rests against the stop pin 27.

While this mechanism is only actuated when the magnetic roller 8, and thereby also the turntable l, rotates in a predetermined direction, the mechanism, shown in FIGS. and 6, acts independently of the direction of rotation of the magnetic roller 8 and the turntable 1.

Depending on the direction from which the magnetic roller 8 enters the internal corner of the template 6, either the toothed segment 29 meshes with the gear pinion 23 (FIG. 5) while the toothed segment 28 remains in its normal position, or vice versa.

What I claim is:

l. A template follower mechanism including a template having internal corners, a magnetic roller bearing against said template, a gear pinion coaxial with said roller, a motor for driving said roller and said gear pinion, a toothed segment cooperating with said gear pinion and having a bore, an adjustable eccentric bolt having a cylindrical shaft for pivotally receiving said toothed segment in said bore and an eccentrical shaft received and fastened in said bore of said template, for eliminating and adjusting the clearance between said toothed segment and said gear pinion, said toothed segment acting like a lever when said gear pinion meshes with said toothed segment after entering said internal corner in order to push said magnetic roller and said gear pinion out of said comers into a direction of course determined by the course of said template, two pins, one secured to said segment and the other to said template, a tension spring between said two pins for moving said toothed segment into the normal position after demeshing of said gear pinion from said toothed segment, and a stop means secured to said template for cooperating with said toothed segment in order to determine the normal position of said toothed segment.

2. A template follower mechanism including a template having corners and two bores close to said corners, a magnetic roller bearing against said template, a gear pinion coaxial with said roller, a motor for driving said roller and said gear pinion when driven in a counterclockwise direction, a second toothed segment cooperating with said gear pinion when driven in a clockwise direction, said first and said second toothed segment being provided with a bore, adjustable eccentric bolts having a cylindrical shaft for pivotally receiving said toothed segments in said bores and an eccentrical shaft received and fastened in said bores of said template, for eliminating and adjusting the clearance between said toothed segments and said gear pinion, said toothed segments acting like a lever when said gear pinion meshes with one of said toothed segments after entering said internal corner in order to push said megnatic roller and said gear pinion out of said corners into a direction of course determined by the course of said template, and means for moving said toothed segments into the normal positions after demeshing of said gear pinion from said toothed segments, said means comprising spring holding members secured to said template, spring holding members secured to said toothed template, and a coil spring received by said spring holding members, said spring holding members and said coil springs being arranged in such a manner that, if the toothed segments are in the normal positions, the coil springs are in straight-lined positions.

3. In a sewing device with guided control of a sewing cycle, in combination, a support means, a turntable pivotally attached to said support means, a template mounted below said turntable and having bores close to said comers, workpiece clamping means mounted above said turntable, a link arm swingably secured to said support means, a supporting arm pivoted on said link arm, a magnetic roller engaged with the edge of said template, a gear pinion coaxial with said roller, a motor arranged in said supporting arm for driving said magnetic roller and said gear pinion, a sewing machine carried by said supporting arm and having a vertically reciprocating needle coaxially with said magnetic roller and said gear pinion, toothed segments cooperating with said gear pinion and having a bore, adjustable eccentric bolts having a cylindrical shaft for pivotally receiving said toothed segments in said bore and an eccentrical shaft received and fastened in said bores of said template, for eliminating and adjusting the clearance between said toothed segments and said gear pinion, said toothed segments acting like a lever when said gear pinion meshes with one of said toothed segments after entering said internal corners in order to push said magnetic roller and said gear pinion out of said corners into a direction of course determined by the course of said template, and means for moving said toothed segments into the normal positions after demeshing of said gear pinion from said toothed segments, said means comprising a spring holding member secured to said toothed segments, and a coil spring received by said spring holding members, said spring holding members and said coil springs being arranged in such a manner that, if the toothed segments are in the normal positions, the coil springs are in straight-lined positions.

4. A sewing device as claimed in claim 3, wherein said template is further provided with additional toothed segments arranged adjacent to each of said internal corners by means of said adjustable eccentric bolts, for cooperating with said gear pinion when said magnetic roller is driven in an opposite direction. 

1. A template follower mechanism including a template having internal corners, a magnetic roller bearing against said template, a gear pinion coaxial with said roller, a motor for driving said roller and said gear pinion, a toothed segment cooperating with said gear pinion and having a bore, an adjustable eccentric bolt having a cylindrical shaft for pivotally receiving said toothed segment in said bore and an eccentrical shaft received and fastened in said bore of said template, for eliminating and adjusting the clearance between said toothed segment and said gear pinion, said toothed segment acting like a lever when said gear pinion meshes with said toothed segment after entering said internal corner in order to push said magnetic roller and said gear pinion out of said corners into a direction of course determined by the course of said template, two pins, one secured to said segment and the other to said template, a tension spring between said two pins for moving said toothed segment into the normal position after demeshing of said gear pinion from said toothed segment, and a stop means secured to said template for cooperating with said toothed segment in order to determine the normal position of said toothed segment.
 2. A template follower mechanism including a template having corners and two bores close to said corners, a magnetic roller bearing against said template, a gear pinion coaxial with said roller, a motor for driving said roller and said gear pinion when driven in a counterclockwise direction, a second toothed segment cooperating with said gear pinion when driven in a clockwise direction, said first and said second toothed segment being provided with a bore, adjustable eccentric bolts having a cylindrical shaft for pivotally receiving said toothed segments in said bores and an eccentrical shaft received and fastened in said bores of said template, for eliminating and adjusting the clearance between said toothed segments and said gear pinion, said toothed segments acting like a lever when said gear pinion meshes with one of said toothed segments after entering said internal corner in order to push said megnatic roller and said gear pinion out of said corners into a direction of course determined by the course of said template, and means for moving said toothed segments into the normal positions after demeshing of said gear pinion from said toothed segments, said means comprising spring holding members secured to said template, spring holding members secured to said toothed template, and a coil spring received by said spring holding members, said spring holding members and said coil springs being arranged in such a manner that, if the toothed segments are in the normal positions, the coil springs are in straight-lined positions.
 3. In a sEwing device with guided control of a sewing cycle, in combination, a support means, a turntable pivotally attached to said support means, a template mounted below said turntable and having bores close to said corners, workpiece clamping means mounted above said turntable, a link arm swingably secured to said support means, a supporting arm pivoted on said link arm, a magnetic roller engaged with the edge of said template, a gear pinion coaxial with said roller, a motor arranged in said supporting arm for driving said magnetic roller and said gear pinion, a sewing machine carried by said supporting arm and having a vertically reciprocating needle coaxially with said magnetic roller and said gear pinion, toothed segments cooperating with said gear pinion and having a bore, adjustable eccentric bolts having a cylindrical shaft for pivotally receiving said toothed segments in said bore and an eccentrical shaft received and fastened in said bores of said template, for eliminating and adjusting the clearance between said toothed segments and said gear pinion, said toothed segments acting like a lever when said gear pinion meshes with one of said toothed segments after entering said internal corners in order to push said magnetic roller and said gear pinion out of said corners into a direction of course determined by the course of said template, and means for moving said toothed segments into the normal positions after demeshing of said gear pinion from said toothed segments, said means comprising a spring holding member secured to said toothed segments, and a coil spring received by said spring holding members, said spring holding members and said coil springs being arranged in such a manner that, if the toothed segments are in the normal positions, the coil springs are in straight-lined positions.
 4. A sewing device as claimed in claim 3, wherein said template is further provided with additional toothed segments arranged adjacent to each of said internal corners by means of said adjustable eccentric bolts, for cooperating with said gear pinion when said magnetic roller is driven in an opposite direction. 